5EXQ

Human cytochrome c Y48H


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.193 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.174 

Starting Model: experimental
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This is version 2.2 of the entry. See complete history


Literature

Altered structure and dynamics of pathogenic cytochrome c variants correlate with increased apoptotic activity.

Fellner, M.Parakra, R.McDonald, K.O.Kass, I.Jameson, G.N.L.Wilbanks, S.M.Ledgerwood, E.C.

(2021) Biochem J 

  • DOI: https://doi.org/10.1042/BCJ20200793
  • Primary Citation of Related Structures:  
    5EXQ, 6ECJ

  • PubMed Abstract: 

    Mutation of cytochrome c in humans causes mild autosomal dominant thrombocytopenia. The role of cytochrome c in platelet formation, and the molecular mechanism underlying the association of cytochrome c mutations with thrombocytopenia remains unknown, although a gain-of-function is most likely. Cytochrome c contributes to several cellular processes, with an exchange between conformational states proposed to regulate changes in function. Here, we use experimental and computational approaches to determine whether pathogenic variants share changes in structure and function, and to understand how these changes might occur. Three pathogenic variants (G41S, Y48H, A51V) cause an increase in apoptosome activation and peroxidase activity. Molecular dynamics simulations of these variants, and two non-naturally occurring variants (G41A, G41T), indicate that increased apoptosome activation correlates with the increased overall flexibility of cytochrome c, particularly movement of the Ω loops. Crystal structures of Y48H and G41T complement these studies which overall suggest that the binding of cytochrome c to apoptotic protease activating factor-1 (Apaf-1) may involve an 'induced fit' mechanism which is enhanced in the more conformationally mobile variants. In contrast, peroxidase activity did not significantly correlate with protein dynamics. Thus, the mechanism by which the variants increase peroxidase activity is not related to the conformational dynamics of the native hexacoordinate state of cytochrome c. Recent molecular dynamics data proposing conformational mobility of specific cytochrome c regions underpins changes in reduction potential and alkaline transition pK was not fully supported. These data highlight that conformational dynamics of cytochrome c drive some but not all of its properties and activities.


  • Organizational Affiliation

    Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Cytochrome c
A, B
104Homo sapiensMutation(s): 1 
Gene Names: CYCSCYC
UniProt & NIH Common Fund Data Resources
Find proteins for P99999 (Homo sapiens)
Explore P99999 
Go to UniProtKB:  P99999
PHAROS:  P99999
GTEx:  ENSG00000172115 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP99999
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.193 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.174 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 56.791α = 90
b = 35.965β = 115.63
c = 59.937γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
PHASERphasing
PHENIXrefinement
PDB_EXTRACTdata extraction
Aimlessdata scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2016-11-30
    Type: Initial release
  • Version 2.0: 2021-02-03
    Changes: Atomic model, Data collection, Database references, Derived calculations, Non-polymer description, Structure summary
  • Version 2.1: 2023-09-27
    Changes: Data collection, Database references, Refinement description
  • Version 2.2: 2024-10-23
    Changes: Structure summary